气候变化领域集成服务门户(CCPortal): Vertical Temperature Profile of Natural Lightning Return Strokes Derived From Optical Spectra

CCPortal

DOI	10.1029/2020JD034438
	Vertical Temperature Profile of Natural Lightning Return Strokes Derived From Optical Spectra
	Boggs L.D.; Liu N.; Nag A.; Walker T.D.; Christian H.J.; da Silva C.L.; Austin M.; Aguirre F.; Rassoul H.K.
发表日期	2021
ISSN	2169897X
卷号	126 期号:8
英文摘要	This study reports on spectroscopy results from a high-speed optical spectrograph of two naturally occurring lightning return strokes. The two strokes occurred near Melbourne, FL and were from two separate flashes that were about 10 min apart and had National Lightning Detection Network (NLDN) peak currents of −19 and −63 kA. The larger peak current stroke was from a dart leader and was the last stroke in a 5 return stroke flash, while the −19 kA stroke originated from a stepped leader and was the only stroke in that flash. From the flash spectra, the return stroke channel temperature was calculated using the neutral lines of 715.7 nm (OI) and 777.4 nm (OI). In addition to the use of the neutral emission lines, the use of novel instrumentation and image processing techniques allowed the temperature to be calculated for nearly the entire visible channel (several km) and for long durations (several hundred μs). This enables temperature estimates on an unprecedented spatial and temporal scale, which show that the vertical temperature profile is not uniform across the channel. The lower altitudes are significantly hotter than higher altitudes near the time of the return stroke, with temperature gradients along the channel as large as 12,000 K/km. The rate of cooling of the channel is also initially 3–4 times larger at lower altitudes in comparison with the segments at higher altitudes. The stroke with the larger peak current shows larger maximum temperatures, larger temperature gradients along the channel, and also cools quicker. © 2021. American Geophysical Union. All Rights Reserved.
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185299
作者单位	Severe Storms Research Center, Sensors and Electromagnetic Applications Lab, Georgia Tech Research Institute, Smyrna, GA, United States; Department of Physics and Space Science Center, University of New Hampshire, Durham, NH, United States; Geospace Physics Lab, Aerospace, Physics and Space Sciences Department, Florida Institute of Technology, Melbourne, FL, United States; Earth System Science Center, University of Alabama Huntsville, Huntsville, AL, United States; Department of Physics and Langmuir Laboratory, New Mexico Institute of Mining and Technology, Socorro, NM, United States
推荐引用方式 GB/T 7714	Boggs L.D.,Liu N.,Nag A.,et al. Vertical Temperature Profile of Natural Lightning Return Strokes Derived From Optical Spectra[J],2021,126(8).
APA	Boggs L.D..,Liu N..,Nag A..,Walker T.D..,Christian H.J..,...&Rassoul H.K..(2021).Vertical Temperature Profile of Natural Lightning Return Strokes Derived From Optical Spectra.Journal of Geophysical Research: Atmospheres,126(8).
MLA	Boggs L.D.,et al."Vertical Temperature Profile of Natural Lightning Return Strokes Derived From Optical Spectra".Journal of Geophysical Research: Atmospheres 126.8(2021).